Nissan Versa

 Sedan Service Manual

Ventilation, heater & air conditioner » Heater & air conditioning system (HA)
Refrigeration system

Refrigerant Cycle

REFRIGERANT FLOW

The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank, through the evaporator, and back to the compressor. The refrigerant evaporation through the evaporator coils are controlled by externally equalized expansion valve, located inside the evaporator case.

Refrigerant System Protection

1. A/C compressor 2. Pressure relief valve 3. Liquid tank 4. Refrigerant pressure sensor 5. Condenser 6. Expansion valve 7. Evaporator 8. Blower motor A. High-pressure gas B. High-pressure liquid C. Low-pressure liquid D. Low-pressure gas E. Suction port F. Discharge port G Outside air

REFRIGERANT PRESSURE SENSOR

The refrigerant system is protected against excessively high or low pressures by the refrigerant pressure sensor, located on the condenser. If the system pressure rises above or falls below the specifications, the refrigerant pressure sensor detects the pressure inside the refrigerant line and sends a voltage signal to the ECM.

The ECM de-energizes the A/C relay to disengage the magnetic compressor clutch when pressure on the high pressure side detected by refrigerant pressure sensor is over about 2,746 kPa (28 kg/cm2, 398 psi), or below about 120 kPa (1.22 kg/cm2, 17.4 psi).

PRESSURE RELIEF VALVE

The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.

When the pressure of refrigerant in the system increases to an abnormal level [more than 2,990 kPa (30.5 kg/ cm2, 433.6 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant into the atmosphere.

Component

1. A/C unit assembly 2. O-ring 3. High-pressure pipe 4. Condenser 5. Liquid tank 6. Refrigerant pressure sensor 7. High-pressure flexible hose 8. Compressor 9. Low-pressure flexible hose

NOTE: Refer to HA "Precaution for Refrigerant Connection".

BASIC INSPECTION

Precautions

Preparation

Component parts

Refrigeration system

Diagnosis and repair workflow

Refrigerant

Oil

Performance test

Compressor

Condenser

Low-pressure flexible hose

High-pressure flexible hose

High-pressure pipe

Expansion valve

Refrigerant pressure sensor

A/C Unit assembly

Evaporator